As high-load work is increasingly common in industrial fields, there is an increased need to study measures that can reduce a load applied to human joints in order to increase the convenience of a worker. According to this demand, a wearable robot, which a worker wears and which moves, has been proposed as one such measure. The present inventive concept proposes a technique for extracting intended torque of a wearer so as to allow the wearable robot to accurately move according to the intent of the wearer.
In a method and apparatus for compensating a stick motion generated at a quadrant changing position in numerical control machine tools disclosed in Korean Unexamined Patent Application Publication No. 10-2008-0079590, a real position estimator estimates a real position of a movable body corresponding to a position instruction signal to generate a real position signal. A differentiator differentiates the real position signal to obtain a speed signal. Then, an integrator integrates the speed signal, thereby generating a displacement signal from a position at which a moving direction of the movable body is reversed. An absolute value calculator obtains an absolute value of the displacement signal. A friction characteristic estimator obtains a rate of change of displacement of friction force or friction torque. A multiplier multiplies the rate of change of the displacement by the speed signal, and obtains a rate of change of time. An integrator 28 integrates the rate of change of time, and estimates the friction force or the friction torque.
However, in spite of this measure, a measure is still required for realizing proper movement corresponding to the intent of the wearer by obtaining friction in real driving in real time, and by compensating a driver with the obtained friction.
Further, a force-torque sensor is generally attached to the wearable robot in order to measure torque applied by a user. This sensor increases the weight of a mechanism as well as the price.
Thus, since the force-torque sensor is used to calculate the wearer-intended torque, a measure to effectively calculate the wearer-intended torque without using this expensive sensor is required.
The foregoing is intended merely to aid in the understanding of the background of the present inventive concept, and is not intended to mean that the present inventive concept falls within the purview of the related art that is already known to those skilled in the art.